Fix memory leak for data source ensemble summary (#8919)

* Do not create summary case group twice

* Fix memory leak of objects contained in childArrayFields
Use deleteAllChildObjects to delete objects instead of clear()
Rename collection function clear() -> deleteAllChildObjects

* Early exit for empty path

* Reduce redundant calls to refreshMetaData

ApplicationLibCode/ProjectDataModel/Summary/RimFileSummaryCase.cpp

@@ -225,6 +225,7 @@ void RimFileSummaryCase::defineEditorAttribute( const caf::PdmFieldHandle* field
 void RimFileSummaryCase::openAndAttachAdditionalReader()
 {
     QString additionalSummaryFilePath = m_additionalSummaryFilePath().path();
+    if ( additionalSummaryFilePath.isEmpty() ) return;
 
     cvf::ref<RifOpmCommonEclipseSummary> opmCommonReader = new RifOpmCommonEclipseSummary;
     opmCommonReader->useEnhancedSummaryFiles( true );